Femoral Component TKA: Extramedullary vs Conventional Intramedullary Guide (EMAX (L2055))

September 8, 2026 updated by: I.R.C.C.S Ospedale Galeazzi-Sant'Ambrogio

Positioning Femoral Component TKA Using an Extramedullary Guide: Comparison With Conventional Intramedullary Guide

The study wants to evaluate the performance of this EM guide in comparison to a traditional IM guide.

75 patients will be included in the extramedullary group (to be compared with a corresponding previous group of 75 patients treated with intramedullary guide).

Study Overview

Status

Recruiting

Conditions

Detailed Description

Total Knee Arthroplasty (TKA) is a widely performed surgical procedure aimed at relieving pain and restoring function in patients with advanced knee arthritis. The success of TKA is contingent upon precise implant positioning, particularly in relation to the femoral component. The femoral component's alignment significantly influences postoperative knee biomechanics, patient satisfaction, and long-term implant survival.

Conventional methods for femoral component positioning involve the use of intramedullary (IM) guides, which are inserted into the femoral canal to align the cutting block for bone preparation. While IM guides offer precise alignment, they can also lead to complications such as intraoperative fractures, fat embolism, activation of coagulation and excessive blood loss.

To address these limitations, extramedullary (EM) guides have emerged as an alternative option. EM guides are placed on the external surface of the femur without entering the medullary canal and avoiding complications that may occur reaming the canal.

In the recent past years, kinematic alignment (KA) has become widespread in use as a new technique for TKR that considers the patient's individual alignment and biomechanics. By restoring the pre-arthritic kinematic axes of the femur and tibia, KA aims to mimic the natural knee joint's function and movement.

In this study a specific EM guide - Anterior Cortex Stylus - is used to address the alignment of the femoral component in the context of a KA approach. The guide uses the anterior cortex of the distal femur as reference for cutting block positioning. The study aims to evaluate the performance of this EM guide in comparison to a traditional IM guide (used in previous group of patients).

This is an open, multi-centre, retro-prospective, observational, controlled study.

The primary aim is to evaluate whether the Anterior Cortex Stylus (in a retro-prospective collected series) is not inferior to the traditional intramedullary guide (previous group of patients) in term of positioning of the femoral component in TKA.

A total of 75 patients will be included in the extramedullary group (to be compared with a corresponding previous group of 75 patients treated with intramedullary guide). Both groups will be treated with a total knee arthroplasty using GMK Sphere (CE marked, class III) and a kinematic alignment approach.

Study Type

Observational

Enrollment (Estimated)

150

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Laura Mangiavini
  • Phone Number: 0039 0283502227

Study Locations

  • Italy
      • Milan, Italy, 20148
        • Completed
        • Istituto Clinico San Siro
      • Milan, Italy, 20157
      • Torino, Italy, 10152
        • Completed
        • Ospedale Cottolengo

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

The study shall include a total of 150 patients: 75 will be included in the extramedullary group, to be compared with a corresponding previous group of 75 patients treated with intramedullary guide. Patients meeting the inclusion criteria (mentioned below) will be recruited separately by each participating institution.

Patient enrolled in the retrospective analysis have been operated upon between January 2021 and September 2025.

Description

Inclusion Criteria:

  • Male or female ≥ 18 years old
  • Indication to primary TKA, for any diagnosis operated with EM or IM guides
  • Signature of the informed consent (only for prospective cohort)
  • Been operated upon between January 2021 and September 2025 (only for retrospective cohort)

Exclusion Criteria:

  • Revision surgery of knee arthroplasty
  • Patients with malignant diseases (at the time of surgery)
  • Patients with proven or suspect infections (at the time of surgery)
  • Pregnancy end/or lactating (auto declaration)
  • Patient with known allergy to the specific metallic components of the prosthesis (at the time of surgery)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Extramedullary (EM) guides: Retroprospective + Prospective cohort
patients trated with extramedullary (EM) guides. This cohort can be both Retroprospective and Prospective
intramedullary (IM) guides: Retrospective cohort
patients trated with intramedullary (IM) guides. This cohort will be only Retrospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Anterior Cortex Stylus
Time Frame: Radiographic angle at 3 moth post-op in the sagittal plane, between the anterior cortex of the distal femur and the femoral component and compare it in the group operated with Anterior Cortex Stylus versus the group operated with IM guide.
Radiographic angle at 3 moth post-op of the femoral component in TKA in an Anterior Cortex Stylus (retro-prospective collected series) compared to intramedullary guide (previous group of patients)
Radiographic angle at 3 moth post-op in the sagittal plane, between the anterior cortex of the distal femur and the femoral component and compare it in the group operated with Anterior Cortex Stylus versus the group operated with IM guide.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Results across study centres
Time Frame: Compare the results in terms of radiographic sagittal angle between study centres at pre-op, surgery and 3 month post-op.
Radiographic angles compared between the centres (at pre-op, surgery and 3 month post-op)
Compare the results in terms of radiographic sagittal angle between study centres at pre-op, surgery and 3 month post-op.
Adverse Events to determinate Instrument safety
Time Frame: During surgery
Number of: adverse events, adverse device effects, serious adverse events and serious adverse device effects
During surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

I.R.C.C.S Ospedale Galeazzi-Sant'Ambrogio

Investigators

  • Principal Investigator: Corrado Sosio, Ospedale Galeazzi S.p.A.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 15, 2025

Primary Completion (Estimated)

October 15, 2027

Study Completion (Estimated)

October 31, 2027

Study Registration Dates

First Submitted

September 2, 2026

First Submitted That Met QC Criteria

September 8, 2026

First Posted (Actual)

September 11, 2026

Study Record Updates

Last Update Posted (Actual)

September 11, 2026

Last Update Submitted That Met QC Criteria

September 8, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • EMAX (L2055)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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